Wastewater Treatment by Polymeric Microspheres: A Review

Abstract

This review addresses polymer microspheres used as adsorbent for wastewater treatment. The removal of various pollutants (including dyes, heavy metal ions, and organic pollutants) is a prominent issue, as they can cause severe health problems. Porous microspheres can provide large specific area and active sites for adsorption or photo degradation. Enhancement in performance is achieved by various modifications, such as the introduction of nanoparticles, magnetic particles, and ZIF-8. Some microspheres were synthesized from synthetic polymers such as vinylic polymer and polydopamine (PDA) through a facile fabrication process. Natural polymers (such as cellulose, alginate, and chitosan) that are biodegradable and eco-friendly are also used. The adsorbents used in industrial application require high adsorption capacity, thermal stability, and recyclability. Batch adsorption experiments were conducted to investigate the optimal conditions, influence of related factors, and adsorption capacities. Insights regarding the adsorption mechanisms were given from the kinetic model, isotherm model, and various characterization methods. The recyclability is investigated through regeneration ratio, or their maintenance of their capability through repeated adsorption-desorption cycles. The high potential of polymer microsphere for the removal of pollutants from wastewater is shown through the high adsorption capacities, environmentally friendliness, and high stability.

Mussel-Inspired Polydopamine Composite Mesoporous Bioactive Glass Nanoparticles: An Exploration of Potential Metal-Ion Loading Platform and In Vitro Bioactivity

“…In fact, ion adsorption is an attractive function of polydopamine coatings, which has been developed for heavy-metal pollution cleanup. 61 Although our results have demonstrated the active adsorption of Cu 2+ and Co 2+ by MBG NPs coated with PDA, according to our present results, it is concluded that the coating of PDA hinders the formation of hydroxyapatite on MBG NPs for relatively short immersion times in SBF (within 7 days).…”

Lignin Smart Nanoparticles for Effective and Eco-Friendly Resource Recovery from Wastewater: Status, Challenges, and Opportunities

“…55,56 The characteristics of an effective adsorbent are high adsorption capacity, thermal stability, efficiency, reuse, and recycle capability. 55,56 From these perspectives, activated carbon, which is the primary adsorbent used at an industrial scale, suffers majorly from high costs, and poor affinity to hydrophilic resources such as anionic dyes, 55 and lignin nano-and microparticles being amphiphilic, are potential competitive adsorbents. Nonetheless, the physicochemical properties of lignin materials vary with process conditions (e.g., pH, temperature, and salt concentration) and in turn will affect the adsorption capacity.…”

Magnetic Core@Shell Fe3O4@Polypyrrole@Sodium Dodecyl Sulfate Composite for Enhanced Selective Removal of Dyestuffs and Heavy Metal Ions from Complex Wastewater

“…In recent years, with the rapid development of industries, the sewage discharge is increasing gradually, and the water pollution problem is becoming more and more serious. − Some dyestuff and heavy metal ion sewage produced by some industries is difficult to degrade and dyestuff molecules , and heavy metal ions can exist in the natural environment for a long time. − The most important thing is that these dyestuffs and ions as carcinogens seriously affect the health of water organisms and human beings. Therefore, necessary treatment is needed before sewage is discharged. − With the development of society, the treatment of dyestuffs and heavy metal ions − in sewage has become the focus of developing modern civilized cities. − However, because the composition of dyestuffs and heavy metal ions is very complex, the degree of pigment is too high, and the influence of acid and alkali is great, it is very hard for sewage treatment at present.…”